diff options
Diffstat (limited to 'drivers/clk/sunxi/clk-sun9i-core.c')
| -rw-r--r-- | drivers/clk/sunxi/clk-sun9i-core.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun9i-core.c b/drivers/clk/sunxi/clk-sun9i-core.c new file mode 100644 index 000000000000..3cb9036d91bb --- /dev/null +++ b/drivers/clk/sunxi/clk-sun9i-core.c @@ -0,0 +1,271 @@ +/* + * Copyright 2014 Chen-Yu Tsai + * + * Chen-Yu Tsai <wens@csie.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/log2.h> + +#include "clk-factors.h" + + +/** + * sun9i_a80_get_pll4_factors() - calculates n, p, m factors for PLL1 + * PLL4 rate is calculated as follows + * rate = (parent_rate * n >> p) / (m + 1); + * parent_rate is always 24Mhz + * + * p and m are named div1 and div2 in Allwinner's SDK + */ + +static void sun9i_a80_get_pll4_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + int div; + + /* Normalize value to a 6M multiple */ + div = DIV_ROUND_UP(*freq, 6000000); + + /* divs above 256 cannot be odd */ + if (div > 256) + div = round_up(div, 2); + + /* divs above 512 must be a multiple of 4 */ + if (div > 512) + div = round_up(div, 4); + + *freq = 6000000 * div; + + /* we were called to round the frequency, we can now return */ + if (n == NULL) + return; + + /* p will be 1 for divs under 512 */ + if (div < 512) + *p = 1; + else + *p = 0; + + /* m will be 1 if div is odd */ + if (div & 1) + *m = 1; + else + *m = 0; + + /* calculate a suitable n based on m and p */ + *n = div / (*p + 1) / (*m + 1); +} + +static struct clk_factors_config sun9i_a80_pll4_config = { + .mshift = 18, + .mwidth = 1, + .nshift = 8, + .nwidth = 8, + .pshift = 16, + .pwidth = 1, +}; + +static const struct factors_data sun9i_a80_pll4_data __initconst = { + .enable = 31, + .table = &sun9i_a80_pll4_config, + .getter = sun9i_a80_get_pll4_factors, +}; + +static DEFINE_SPINLOCK(sun9i_a80_pll4_lock); + +static void __init sun9i_a80_pll4_setup(struct device_node *node) +{ + sunxi_factors_register(node, &sun9i_a80_pll4_data, &sun9i_a80_pll4_lock); +} +CLK_OF_DECLARE(sun9i_a80_pll4, "allwinner,sun9i-a80-pll4-clk", sun9i_a80_pll4_setup); + + +/** + * sun9i_a80_get_gt_factors() - calculates m factor for GT + * GT rate is calculated as follows + * rate = parent_rate / (m + 1); + */ + +static void sun9i_a80_get_gt_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u32 div; + + if (parent_rate < *freq) + *freq = parent_rate; + + div = DIV_ROUND_UP(parent_rate, *freq); + + /* maximum divider is 4 */ + if (div > 4) + div = 4; + + *freq = parent_rate / div; + + /* we were called to round the frequency, we can now return */ + if (!m) + return; + + *m = div; +} + +static struct clk_factors_config sun9i_a80_gt_config = { + .mshift = 0, + .mwidth = 2, +}; + +static const struct factors_data sun9i_a80_gt_data __initconst = { + .mux = 24, + .muxmask = BIT(1) | BIT(0), + .table = &sun9i_a80_gt_config, + .getter = sun9i_a80_get_gt_factors, +}; + +static DEFINE_SPINLOCK(sun9i_a80_gt_lock); + +static void __init sun9i_a80_gt_setup(struct device_node *node) +{ + struct clk *gt = sunxi_factors_register(node, &sun9i_a80_gt_data, + &sun9i_a80_gt_lock); + + /* The GT bus clock needs to be always enabled */ + __clk_get(gt); + clk_prepare_enable(gt); +} +CLK_OF_DECLARE(sun9i_a80_gt, "allwinner,sun9i-a80-gt-clk", sun9i_a80_gt_setup); + + +/** + * sun9i_a80_get_ahb_factors() - calculates p factor for AHB0/1/2 + * AHB rate is calculated as follows + * rate = parent_rate >> p; + */ + +static void sun9i_a80_get_ahb_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u32 _p; + + if (parent_rate < *freq) + *freq = parent_rate; + + _p = order_base_2(DIV_ROUND_UP(parent_rate, *freq)); + + /* maximum p is 3 */ + if (_p > 3) + _p = 3; + + *freq = parent_rate >> _p; + + /* we were called to round the frequency, we can now return */ + if (!p) + return; + + *p = _p; +} + +static struct clk_factors_config sun9i_a80_ahb_config = { + .pshift = 0, + .pwidth = 2, +}; + +static const struct factors_data sun9i_a80_ahb_data __initconst = { + .mux = 24, + .muxmask = BIT(1) | BIT(0), + .table = &sun9i_a80_ahb_config, + .getter = sun9i_a80_get_ahb_factors, +}; + +static DEFINE_SPINLOCK(sun9i_a80_ahb_lock); + +static void __init sun9i_a80_ahb_setup(struct device_node *node) +{ + sunxi_factors_register(node, &sun9i_a80_ahb_data, &sun9i_a80_ahb_lock); +} +CLK_OF_DECLARE(sun9i_a80_ahb, "allwinner,sun9i-a80-ahb-clk", sun9i_a80_ahb_setup); + + +static const struct factors_data sun9i_a80_apb0_data __initconst = { + .mux = 24, + .muxmask = BIT(0), + .table = &sun9i_a80_ahb_config, + .getter = sun9i_a80_get_ahb_factors, +}; + +static DEFINE_SPINLOCK(sun9i_a80_apb0_lock); + +static void __init sun9i_a80_apb0_setup(struct device_node *node) +{ + sunxi_factors_register(node, &sun9i_a80_apb0_data, &sun9i_a80_apb0_lock); +} +CLK_OF_DECLARE(sun9i_a80_apb0, "allwinner,sun9i-a80-apb0-clk", sun9i_a80_apb0_setup); + + +/** + * sun9i_a80_get_apb1_factors() - calculates m, p factors for APB1 + * APB1 rate is calculated as follows + * rate = (parent_rate >> p) / (m + 1); + */ + +static void sun9i_a80_get_apb1_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u32 div; + u8 calcm, calcp; + + if (parent_rate < *freq) + *freq = parent_rate; + + div = DIV_ROUND_UP(parent_rate, *freq); + + /* Highest possible divider is 256 (p = 3, m = 31) */ + if (div > 256) + div = 256; + + calcp = order_base_2(div); + calcm = (parent_rate >> calcp) - 1; + *freq = (parent_rate >> calcp) / (calcm + 1); + + /* we were called to round the frequency, we can now return */ + if (n == NULL) + return; + + *m = calcm; + *p = calcp; +} + +static struct clk_factors_config sun9i_a80_apb1_config = { + .mshift = 0, + .mwidth = 5, + .pshift = 16, + .pwidth = 2, +}; + +static const struct factors_data sun9i_a80_apb1_data __initconst = { + .mux = 24, + .muxmask = BIT(0), + .table = &sun9i_a80_apb1_config, + .getter = sun9i_a80_get_apb1_factors, +}; + +static DEFINE_SPINLOCK(sun9i_a80_apb1_lock); + +static void __init sun9i_a80_apb1_setup(struct device_node *node) +{ + sunxi_factors_register(node, &sun9i_a80_apb1_data, &sun9i_a80_apb1_lock); +} +CLK_OF_DECLARE(sun9i_a80_apb1, "allwinner,sun9i-a80-apb1-clk", sun9i_a80_apb1_setup); |